The SF-36: A simple, effective measure of mobility-disability for epidemiological studies

  • H. E. Syddall
  • H. J. Martin
  • R. H. Harwood
  • C. Cooper
  • A. Aihie Sayer



Mobility disability is a major problem in older people. Numerous scales exist for the measurement of disability but often these do not permit comparisons between study groups. The physical functioning (PF) domain of the established and widely used Short Form-36 (SF-36) questionnaire asks about limitations on ten mobility activities.


To describe prevalence of mobility disability in an elderly population, investigate the validity of the SF-36 PF score as a measure of mobility disability, and to establish age and sex specific norms for the PF score.


We explored relationships between the SF-36 PF score and objectively measured physical performance variables among 349 men and 280 women, 59–72 years of age, who participated in the Hertfordshire Cohort Study (HCS). Normative data were derived from the Health Survey for England (HSE) 1996.


32% of men and 46% of women had at least some limitation in PF scale items. Poor SF-36 PF scores (lowest fifth of the gender-specific distribution) were related to: lower grip strength; longer timed-up-and-go, 3m walk, and chair rises test times in men and women; and lower quadriceps peak torque in women but not men. HSE normative data showed that median PF scores declined with increasing age in men and women.


Our results are consistent with the SF-36 PF score being a valid measure of mobility disability in epidemiological studies. This approach might be a first step towards enabling simple comparisons of prevalence of mobility disability between different studies of older people. The SF-36 PF score could usefully complement existing detailed schemes for classification of disability and it now requires validation against them.

Key words

Epidemiology physical functioning disability ageing mobility 


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  1. 1.
    Ebrahim S, Wannamethee SG, Whincup P, et al. Locomotor disability in a cohort of British men: the impact of lifestyle and disease. Int J Epidemiol 2000;29:478–486.CrossRefPubMedGoogle Scholar
  2. 2.
    Harwood RH, Prince MJ, Mann AH, et al. Associations between diagnoses, impairments, disabilities and handicaps in a population of elderly people. Int J Epidemiol 1998; 27:261–268.CrossRefPubMedGoogle Scholar
  3. 3.
    International classification of functioning, disability and health. WHO Health Organisation, 2001.Google Scholar
  4. 4.
    Ebrahim S. Clinical and public health perspectives and applications of health-related quality of life measurement. Soc Sci. Med 1995;41:1383–1394.CrossRefPubMedGoogle Scholar
  5. 5.
    Mahoney FI, Barthel DW. Functional evaluation: the Barthel Index. Md State Med J 1965;14:61–65.PubMedGoogle Scholar
  6. 6.
    Bond, J. and Carstairs, V. Services for the elderly. 1982. Scottish Home and Health Department. Scottish Health Service Studies.Google Scholar
  7. 7.
    Harwood RH, Sayer AA, Hirschfeld M. Current and future worldwide prevalence of dependency, its relationship to total population, and dependency ratios. Bull World Health Organ. 2004 Apr;82(4):251–258.PubMedGoogle Scholar
  8. 8.
    Harwood RH, Ebrahim S and Kalache A; Locomotor Disability in The epidemiology of Old Age; London BMJ/WHO 1996: 378–388Google Scholar
  9. 9.
    Ware JE, Jr., Gandek B. Overview of the SF-36 Health Survey and the International Quality of Life Assessment (IQOLA) Project. J Clin Epidemiol. 1998;51:903–912.CrossRefPubMedGoogle Scholar
  10. 10.
    Prescott-Clarke, P. and Primatesta, P. Health Survey for England’ 96. Vol I: Findings and Vol II: Methodology and Documentation. 1998. London, HMSO.Google Scholar
  11. 11.
    Ferrucci L, Guralnik JM, Studenski S, et al. Designing randomized, controlled trials aimed at preventing or delaying functional decline and disability in frail, older persons: a consensus report. J Am Geriatr.Soc. 2004;52:625–634.CrossRefPubMedGoogle Scholar
  12. 12.
    Brazier JE, Harper R, Jones NM, et al. Validating the SF-36 health survey questionnaire: new outcome measure for primary care. BMJ 1992;305:160–164.CrossRefPubMedGoogle Scholar
  13. 13.
    Singh JA, Borowsky SJ, Nugent S, et al. Health-related quality of life, functional impairment, and healthcare utilization by veterans: veterans’ quality of life study. J Am Geriatr.Soc 2005;53:108–113.CrossRefPubMedGoogle Scholar
  14. 14.
    Guralnik JM, Ferrucci L, Pieper CF, et al. Lower extremity function and subsequent disability: consistency across studies, predictive models, and value of gait speed alone compared with the short physical performance battery. J Gerontol A Biol Sci Med Sci 2000; 55: M221–M231.PubMedGoogle Scholar
  15. 15.
    Ostir GV, Markides KS, Black SA, et al. Lower body functioning as a predictor of subsequent disability among older Mexican Americans. J Gerontol A Biol Sci Med Sci 1998; 53: M491–M495.PubMedGoogle Scholar
  16. 16.
    Syddall HE, Sayer AA, Dennison EM et al. Cohort Profile: The Hertfordshire Cohort Study. Int J Epidemiol 2005.Google Scholar
  17. 17.
    Sayer AA, Syddall HE, Gilbody HJ, et al. Does sarcopenia originate in early life? Findings from the Hertfordshire Cohort Study. J Gerontol 2004;59A:930–934.Google Scholar
  18. 18.
    Sayer AA, Syddall HE, Dennison EM et al. Birth weight, weight at one year and body composition in older men: findings from the Hertfordshire Cohort Study. Am J Clin Nutr 2004;80:199–203.PubMedGoogle Scholar
  19. 19.
    Ware JE, Kosinski M, and Gandek B. SF-36 Health Survey: Manual and Interpretation Guide. 2000. Lincoln, RI, Quality Metric Incorporated.Google Scholar
  20. 20.
    Dallosso HM, Morgan K, Bassey EJ, et al. Levels of customary physical activity among the old and the very old living at home. J Epidemiol Community Health 1988; 42: 121–127.CrossRefPubMedGoogle Scholar
  21. 21.
    Lohman TG, Roche AF, Martorell R, eds. Anthropometric standardization reference manual. Champaign, Illinois: Human Kinetic Books; 1988Google Scholar
  22. 22.
    Mathiowetz V, Weber K, Volland G, et al. Reliability and validity of grip and pinch strength evaluations. J Hand Surg [Am] 1984; 9: 222–226.Google Scholar
  23. 23.
    Podsiadlo D and Richardson S. The timed “up & go”: A test of basic functional mobility for frail elderly persons. Journal of American Geriatric Society 39:142–148, 1991.Google Scholar
  24. 24.
    Tinetti ME, Inouye SK, Gill TM, et al. Shared risk factors for falls, incontinence, and functional dependence. Unifying the approach to geriatric syndromes. JAMA 1995; 273: 1348–1353.CrossRefPubMedGoogle Scholar
  25. 25.
    E. J. Bassey, M. A. Fiatarone, E. F. O’Neill, et al. Leg extensor power and functional performance in very old men and women. Clin Sci (Lond) (3):321–327, 1992.Google Scholar
  26. 26.
    R. C. Briggs, M. R. Gossman, R. Birch, et al. Balance performance among noninstitutionalized elderly women. Phys.Ther. 69(9):748–756, 1989.PubMedGoogle Scholar
  27. 27.
    Martin HJ, Yule V, Syddall HE, et al. Is hand held dynamometry useful for the measurement of quadriceps strength in older people? A comparison with gold standard Biodex dynamometry. Gerontology 2006;52:154–159CrossRefPubMedGoogle Scholar
  28. 28.
    Joint Health Surveys Unit of Social and Community Planning Research and University College London, Health Survey for England, 1996 [computer file]. 3rd ed. Colchester, Essex: UK Data Archive [distributor], 26 March 2001. SN: 3886.Google Scholar
  29. 29.
    Bobak M, Kristenson M, Pikhart H, et al. Life span and disability: a cross sectional comparison of Russian and Swedish community based data. BMJ 2004; 329(7469):767.CrossRefPubMedGoogle Scholar
  30. 30.
    Kuh D, Bassey EJ, Butterworth S, et al. Grip strength, postural control, and functional leg power in a representative cohort of British men and women: associations with physical activity, health status, and socioeconomic conditions. J Gerontol A Biol Sci Med Sci. 2005 Feb;60(2):224–231.PubMedGoogle Scholar
  31. 31.
    Jenkinson C, Coulter A, Wright L. Short form 36 (SF36) health survey questionnaire: normative data for adults of working age. BMJ 1993;306:1437–440.CrossRefPubMedGoogle Scholar
  32. 32.
    Julious SA, George S, Campbell MJ. Sample sizes for studies using the short form 36 (SF-36). JECH 1995; 49: 642–644.Google Scholar

Copyright information

© Serdi and Springer Verlag France 2009

Authors and Affiliations

  • H. E. Syddall
    • 1
  • H. J. Martin
    • 1
  • R. H. Harwood
    • 2
  • C. Cooper
    • 1
  • A. Aihie Sayer
    • 1
    • 3
  1. 1.MRC Epidemiology Resource CentreUniversity of SouthamptonSouthamptonUK
  2. 2.Health Services for Older PeopleNottingham City HospitalNottinghamUK
  3. 3.University Geriatric MedicineUniversity of SouthamptonSouthamptonUK

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